[Windows] Fix pytest_cache folder removal

17:10:43  Remove-Item : Object reference not set to an instance of an object.
17:10:43  At C:\Jenkins\workspace\Drive\Drive-test-volume-specific\tools\windows\deploy_j
17:10:43  enkins_slave.ps1:391 char:3
17:10:43  +         Remove-Item -Path ".pytest_cache" -Verbose
17:10:43  +         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
17:10:43      + CategoryInfo          : NotSpecified: (:) [Remove-Item], NullReferenceEx 
17:10:43     ception
17:10:43      + FullyQualifiedErrorId : System.NullReferenceException,Microsoft.PowerShe 
17:10:43     ll.Commands.RemoveItemCommand